Several types of tape drives include a transducer having a plurality of read/write transducing elements for use with a plurality of channels. The transducer can include a plurality of read/write heads having the capability to read and write data to multiple tracks or channels on a flexible medium such as tape. The transducer can also include at least one servo head for reading servo information from the tape. In some tape drives, the read and write transducers are merged. Some tape drives do not include a separate servo element, and servoing is done by the data head. In some instances, the transducer can include at least two servo heads positioned at or near the edges of the tape. The transducer, therefore, includes a plurality of read/write heads and at least one servo head that are positioned on a ceramic bar. The position of each of the heads is fixed.
The tape includes servo information written on the edges of the tape. The servo head reads the servo information and produces a position signal used to determine the position of the transducing head with respect to the tape. The position signal is also a control signal in a feedback control loop used to position the transducer and keep the read/write heads on track.
In a multi-channel read/write recording system like the one described above, any expansion or contraction of the recording medium results in an error in placement of the track on the tape relative to the read/write head associated with that track. In other words, if the tape shrinks or expands, the position of the track with respect to the read/write head shifts. Past solutions have included formulating tapes that do not contract or expand as much, usually resulting in higher cost tape, or limiting the spacing between tracks such that the amount of tape contraction or expansion is small compared to the separation between tracks. The later solution limits the ultimate capacity of the tape product.